Human-derived metastin (also called KiSS-1 peptide) (WO 00/24890) and mouse or rat-derived metastin (WO 01/75104) are known. Sustained release preparations containing metastin are also known (WO 02/85399).
Reportedly, metastin has an effect of suppressing cancer metastasis and is thus effective for preventing or treating cancers (for example, lung cancer, gastric cancer, liver cancer, pancreatic cancer, colorectal cancer, rectal cancer, colonic cancer, prostate cancer, ovarian cancer, cervical cancer, breast cancer, renal cancer, bladder cancer, brain tumor, etc.); metastin also has an effect of controlling the pancreatic function and is effective for preventing or treating pancreatic diseases (e.g., acute or chronic pancreatitis, pancreatic cancer, etc.); and metastin further has an effect of controlling placental function and is effective for preventing or treating choriocarcinoma, hydatid mole, invasive mole, miscarriage, fetal hypoplasia, abnormal glucose metabolism, abnormal lipid metabolism or abnormal delivery (WO 00/24890, WO 01/75104 and WO 02/85399).